title: Vitamin D in "early" primary Sjögren's syndrome: does it play a role in influencing disease phenotypes?
abstract: Beyond its well-established role in the maintenance of mineral homeostasis, 25-OH-vitamin D deficiency seems to be involved in the development and severity of several autoimmune diseases. To date, contrasting data have been reported regarding the presence of hypovitaminosis D in primary Sjögren's syndrome (pSS). To assess the prevalence of hypovitaminosis D in pSS at an early stage of the disease and to evaluate its impact on pSS clinical manifestations and disease activity, unselected consecutive subjects with recent onset dry mouth and/or dry eyes who underwent a comprehensive diagnostic algorithm for pSS (AECG criteria) were prospectively included in the study. The levels of 25[OH]-D3 were measured by monoclonal antibody immunoradiometric assay. Conditions of 25[OH]-D3 severe deficiency, deficiency, and insufficiency were defined as levels <10, <20, and 20-30 ng/ml, respectively, and their frequencies were investigated in pSS patients and controls. The levels of 25[OH]-D3 were also correlated with patients' demographic, clinical, and serologic features. Seventy-six consecutive females were included: 30/76 patients fulfilled the AECG criteria for pSS. The remaining 46/76 patients represented the control group. No statistical differences were found in the serum levels of 25[OH]-D3 between pSS patients [median levels = 20 ng/ml (IQR 9.3-26)] and controls [median levels = 22.5 ng/ml (IQR 15.6-33)]. In particular, the frequency of 25[OH]-D3 severe deficiency was not significantly different in patients with pSS when compared to controls (23 vs. 17.4 %, p value = 0.24). We found a significant correlation between serum 25[OH]-D3 levels and white blood cells count (r = 0.29, p = 0.01). More specifically, leukocytopenia was significantly associated with 25[OH]-D3 severe deficiency, being documented in 40 % of the subjects with a 25[OH]-D3 severe deficiency and in 11 % of the subjects without a severe vitamin D deficiency (p = 0.02). We did not observe any further association or correlation between hypovitaminosis D and pSS glandular and extra-glandular features. Although the role of hypovitaminosis D in pSS pathogenesis remains controversial, the results of this study encourage the assessment of vitamin D in specific pSS subsets that could mostly benefit from a supplementation.
authors.affiliation: Rheumatology Unit, University of Pisa, Via Roma, 67, 56126, Pisa, Italy, chiara.baldini74@gmail.com.
authors.forename: Chiara
authors.initials: C
authors.lastname: Baldini
authors.forename: Andrea
authors.initials: A
authors.lastname: Delle Sedie
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Luciano
authors.forename: Pasquale
authors.initials: P
authors.lastname: Pepe
authors.forename: Francesco
authors.initials: F
authors.lastname: Ferro
authors.forename: Rosaria
authors.initials: R
authors.lastname: Talarico
authors.forename: Chiara
authors.initials: C
authors.lastname: Tani
authors.forename: Marta
authors.initials: M
authors.lastname: Mosca
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002112:Calcifediol / Q000097:blood*; D005260:Female; D006801:Humans; D015592:Immunoradiometric Assay; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011237:Predictive Value of Tests; D015995:Prevalence; D011446:Prospective Studies; D012720:Severity of Illness Index; D012859:Sjogren's Syndrome / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D014808:Vitamin D Deficiency / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D002112:Calcifediol